Today we begin the Pac-12's preseason countdown of the league's top 25 players. As always, this is a brutally difficult list to make.

The preseason list is more about what a player has already accomplished with a dusting of speculation, not a straight forward projection of who we think the top 25 players are. For example, a player like Washington linebacker Shaq Thompson will likely end up on the postseason top 25, but might not start off on the preseason list. The Pac-12 blog is confident he'll end up being one of the top 25 players in the league in 2013, but there are others with stronger credentials as of today. Same for someone like USC's Dion Bailey, who might end up being one of the best safeties in the country. But since he's spent the past couple of seasons at linebacker, we give the nod to a few of the league's more established safeties. Oregon State's Isaac Seumalo and Storm Woods also fall into this category.

It's a fairly similar approach with what we took last season. For example, we had Isi Sofele and Curtis McNeal on the list because they were coming off 1,000-yard seasons the year before. Then someone like Ka'Deem Carey comes along and blows away the country in rushing. Chase Thomas was highly rated in the preseason, but Trent Murphy got the postseason nod. And, unfortunately, someone like John Boyett (No. 16) was rated in the preseason, but injury kept him off the postseason list. Anthony Barr and Will Sutton overshadowed preseason players like T.J. McDonald and Nickell Robey.

We had a feeling Marcus Mariota and Brett Hundley would be special, but wanted to wait until they proved it. And they did, which is why they ended up on the postseason list.

So expect the list in January of 2014 to look a lot different.

As a reminder, there 12 players coming back from last season's postseason top 25.